[ofw] OpenSM and IB_PORT_CAP_IS_SM

[Fab Tillier]

Hal Rosenstock wrote on Thu, 20 May 2010 at 03:48:16

> On Thu, May 20, 2010 at 3:21 AM, Fab Tillier <ftillier at microsoft.com>
> wrote:
>> I see in the OpenSM code that it sets the IS_SM port capability bit.
>> I didn't see anywhere that it would get cleared when exiting (normally
>> or abnormally.)  I would expect IBAL to keep track of what bits a user-
>> mode client set, and clear them when that user-mode client goes away.
>> Is there any such code, and is it just broken, or is that
>> functionality not there at all?
>> 
>> We're trying to use sminfo to detect if the SM crashed, and sminfo
>> returns the same data whether opensm is running or not, once opensm has
>> been run.
> 
> It's for this very reason that in Linux it's done in the kernel when
> the appropriate fd gets closed.
> 
> Does a similar thing occur on Windows on process/task crash ? Is the
> fd closed or left "stranded" ?

The file object gets closed when the process exits, whether normally or not.  I believe IBAL doesn't track which clients set which bits, and doesn't clean up.  I'm happy to hear that winmad does this properly - what's the timeline for switching opensm to winmad (or libibumad?)

-Fab